#!/usr/bin/perl
#
# Destroy a chroot created by sbuild-createchroot
#
# Copyright © 2016 Johannes Schauer Marin Rodrigues <josch@debian.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see
# <http://www.gnu.org/licenses/>.
#
#######################################################################

use strict;
use warnings;

package Conf;

sub setup {
    my $conf = shift;

    my %destroychroot_keys = (
	'CHROOT_SUFFIX'				=> {
	    DEFAULT => '-sbuild'
	},
    );

    $conf->set_allowed_keys(\%destroychroot_keys);
}


package Options;

use Sbuild::OptionsBase;
use Sbuild::Conf qw();

BEGIN {
    use Exporter ();
    our (@ISA, @EXPORT);

    @ISA = qw(Exporter Sbuild::OptionsBase);

    @EXPORT = qw();
}

sub set_options {
    my $self = shift;

    $self->add_options(
	"chroot-suffix=s" => sub {
	    $self->set_conf('CHROOT_SUFFIX', $_[1]);
	},
	"arch=s" => sub {
	    $self->set_conf('BUILD_ARCH', $_[1]);
	},
    );
}

package main;

use POSIX;
use Getopt::Long qw(:config no_ignore_case auto_abbrev gnu_getopt);
use Sbuild qw(usage_error);
use Sbuild::Utility;
use Sbuild::ChrootInfoSchroot;

my $conf = Sbuild::Conf::new();
Conf::setup($conf);
exit 1 if !defined($conf);
my $options = Options->new($conf, "sbuild-destroychroot", "8");
exit 1 if !defined($options);

usage_error("sbuild-destroychroot",
	    "Incorrect number of options") if (scalar @ARGV != 1);

my $chroot = Sbuild::Utility::get_dist($ARGV[0]);

my $chroot_info = Sbuild::ChrootInfoSchroot->new($conf);
my $session = $chroot_info->create("source",
    $chroot,
    undef, # TODO: Add --chroot option
    $conf->get('BUILD_ARCH'));

if (!defined $session) {
    die "Error creating chroot info\n";
}

my $chroot_id = $session->get('Chroot ID');

$chroot_id =~ s/^source://;

opendir my $dir, "/etc/schroot/chroot.d" or die "Cannot open /etc/schroot/chroot.d: $!";
my @files = readdir $dir;
closedir $dir;

my $config_path;
foreach my $file (@files) {
    my $ininame = "/etc/schroot/chroot.d/$file";
    -f $ininame || next;
    open F, $ininame or die "cannot open $ininame\n";
    my $firstline = <F>;
    chomp $firstline;
    close F;
    $firstline eq "[$chroot_id]" || next;
    $config_path = $ininame;
    last;
}

if (! defined $config_path) {
    die "Cannot find configuration file for $chroot_id in /etc/schroot/chroot.d\n";
}

my $chroot_type;
my $chroot_path;
open F, $config_path or die "cannot open $config_path\n";
while (<F>) {
    if (/^type=(.*)/) {
	$chroot_type = $1;
    }
    if (/^directory=(.*)/) {
	$chroot_path = $1;
    }
    if (/^file=(.*)/) {
	$chroot_path = $1;
    }
}
close F;

if (! defined $chroot_type) {
    die "type key missing from config\n";
}

if (! defined $chroot_path) {
    die "directory or file key missing from config\n";
}

if ($chroot_type ne "file" && $chroot_type ne "directory") {
    die "unknown chroot type: $chroot_type\n";
}

print "Before deleting the chroot, make sure that it is not in use anymore.\n";
print "Specifically, make sure that no open schroot session is using it\n";
print "anymore by running:\n";
print "\n";
print "    schroot --all-sessions --list\n";
print "\n";
if ($chroot_type eq "directory") {
    print "Make sure that no other process is using the chroot directory anymore, \n";
    print "for example by running:\n";
    print "\n";
    print "    lsof $chroot_path\n";
    print "\n";
    print "Delete the chroot, for example by running:\n";
    print "\n";
    print "    rm --recursive --one-file-system $chroot_path\n";
    print "\n";
    if (-e "$Sbuild::Sysconfig::paths{'SBUILD_SYSCONF_DIR'}/chroot/$chroot") {
        print "Delete the chroot link, for example by running:\n";
        print "\n";
        print "    rm $Sbuild::Sysconfig::paths{'SBUILD_SYSCONF_DIR'}/chroot/$chroot\n";
        print "\n";
    }
} else {
    print "Delete the tarball, for example by running:\n";
    print "\n";
    print "    rm $chroot_path\n";
    print "\n";
}
print "Finally, delete the schroot configuration file, for example by running:\n";
print "\n";
print "    rm $config_path\n";
print "\n";